1. Field of the Invention
The present invention relates generally to flow control valves, and more particularly to leak arresting mechanical flow control valves that regulate fluid flow between a minimum flow rate and a maximum flow rate.
2. Description of Related Art
Valves used in the regulation of fluid flow are well known in the art. Valves can be used to maintain fluid flow in a particular direction, or as a safety feature to prevent too high of a flow rate or too low of a flow rate. Some valves are mechanical devices that use the pressure in a fluid flow to compress a spring or other resisting member, thereby allowing the fluid either to pass through the valve or be blocked by the valve.
The present invention is directed to a flow regulating (or safety) valve which allows a constant fluid flow in a predetermined range, as opposed to a pulse flow. Valves used for this purpose are too numerous to identify, but the present invention includes a new feature not found in the prior art valves, namely, a purely mechanical leak detecting function. That is, a mechanical valve which regulates the fluid flow to maintain a flow rate within a predetermined minimum and maximum flow rate, and further mechanically closes the valve when either a small or large downstream leak occurs. Thus, while prior art safety valves will close shut, and thereby stop the fluid flow if a major leak occurs due to the sudden increase in the fluid flow rate, the prior art valves lack the ability to close shut in the event of a small leak such as might occur due to a small breach in the downstream fluid line or the failure of a downstream component. This situation could be of critical importance if, say, the fluid is hazardous or flammable, if the fluid line is not regularly maintained due to its location or conditions of use, or if subsequent damage from such a line breach would be economically or environmentally unacceptable. The response of the valve may be the only indication that a small leak has occurred. The present invention solves the problem that the prior art valves fail to address.